Electric bueglae alarm



(No Model.)

F. G. LYON.

ELEGTRIG BURGL'AR ALARM.

No. 316,376. Patented Apr. 21, 1885.

uarded fiuz'zclz'rg UNITED STATES PATENT OEFIOE.

.ERANK e. LYON, OF JERSEY crrY, NEW JERSEY, ASSIGNOR .ro THE HOLMESELECTRIC PROTECTIVE COMPANY, OF NEW YORK, N. Y.

EL EG-T/RIC BURGLAR-AL'ARM.

Application filed September 29, 1884. (No model.)

SPECIFICATION Timing part of Letters Patent No. 316,376, dated April 21,1885.

all whom it may conlxern: Be it known that I, FRANK G. LYON, of J erseyCity, in the county of Hudson and State v of New Jersey, have inventedacertain new and useful Improvement in Electric Burglar- Alarms, of whichthe following is a specification.

This improvement relates to electricburglaralarms of the kind wherein anelectric circuit extends from a house or other building which itisdesired to guard to an ofiice where watchmen arekept.

It has occasionally happened with these burglar-alarms that burglarshave forced open a door leading to a guarded building, hastily seizedsome valuables therein, and escaped before the watchman at the officecould after hearing the alarm caused by the entrance of the burglarsreach the guarded building.

The object of my improvement is to prevent burglars from successfullyworking in the manner described.

To this end the improvement consists in the combination of an electriccircuit extending between a guarded building and an office 5 analogousfastenings of the door may be broken will not act to break the chain,and of such length that it will permit the door or like article to beopened wide enough to enable the circuit-closing device to operate.

A burglar breaking the lock, bolt. or analogous fastening of the doorby; force exerted with a jimmy in the ordinary manner will find the doorstill secured by the chain, which will not have been broken in the actof breaking the lock, bolt, or analogous fastening. He will, however,have opened the door far enough to cause the circuit-closing device tooperate, and hence the watchman at the office will have been apprised ofhis action. While a he is occupied in endeavors to sever the chain thewatchmen will be afforded time to proceed toward the building. Throughmy improve ment, therefore, the kind of burglaries to which I havereferred will be more easily frustrated.

In the accompanying drawings, Figure 1 is a diagram illustrating anoffice where watchmen are kept, the inner side of a pair of doorsbelonging to aguarded building, and'an electric burglar-alarm embodyingmy improvement. Fig. 2 is a view of a circuit-closing device used in theburglar-alarm, and Fig. 3 is a view of chain-sections and a padlock.

Similar letters of reference designate corresponding parts in all thefigures.

I have marked the word Ollice upon that part of Fig. 1 which is intendedto represent the office where watchmen are kept, and I have also markedthe words Guarded Building upon the part designed to represent the 0guarded building.

A A designate a galvanometer, A designating the coils and A the needle.The coils are connected together in the usual manner.

From the pivot of the galvanometer-needle 7 5 a wire, B, extends to anelectromagnetic alarm-bell, G, thence a wire, B, extends to an electricbattery, D, and thence a wire, B extends to contact-points E E, inconjunction with which the needle A of the galvanometer operates.Thewires BB B the electro-magnetic bell O, and the battery D are all inone local circuit, which is arranged in the office. Whenever thegalvanometer-needle is deflected against either of the contact-points EE, it closes the local circuit and causes the electromagnetic bell tosound an alarm.

F designates an electric battery (shown as A arranged in the office.)One pole is connected by a wire, G, with one of the coils of the gal- 0vanometer. The other coil of the galvanometer is connected by a wire, G,with a switch or key, H, which, as here shown, is pivotally' secured tothe inner side of a door, I, belonging to the guarded building, so thatit may 5 be swung into and out of contact with a congact-point, H, whichis also affixed to the said oor.

From the contact-point H a wire, G extends to a resistance-coil, J,located in the guarded rco frame of the door.

building. This wire, before reaching the resistance-coil, is alsoelectrically connected to a movable metal pin, K, comprised in acircuit-closing device, which is operated by the door I.

From the resistance-coil J a wire, G, extends to the battery F. Thiswire is also connected to a metal contact-piece, K, which is comprisedin the short-circuiting device be fore referred to.

The circuit-closing device is secured to the It has a base-plate, K,which may be made of metal. The metal pin K before mentioned slidesthrough it and another bearing which extends from the plate. This pincarries a metal contact-piece, K. A spring, K", surrounding this pin Kbetween its rear bearing and the contact-piece K", impels the springoutward whenever it can. The contact'piece K is fastened to a block. Kof wood or other insulating material, that is affixed to the base-plateK. This contact-piece K is resilient.

' When the door Iis closed,it presses the pin K inward against theresistance of the spring K. The contact-piece K is thus carried awayfrom the plate K, and also away from the contact-piece K. Thecontact-pieee K owing to its resilience, also moves a slight distanceaway from the plate K. 4

When the doorI is opened even ashort distance, the pin K will moveoutward, and the contact-piece K will make contact with contact-piece Kand force the latter against the plate K. The resistance-coil J willthus be short-circuited'and the galvanometer-needle will be deflected soas to cause the sounding of an alarm at the oifice.

The doc: I, shown, operates in conjunction with a door, I. The door I isfastened, as usual, by bolts, and the door I, whichis the master door,is fastened to it by a lock, bolt, or analogous fastening, L. Suchfastening will hold the door closed tightly.

M M designate two sections of chain fastened one to the inner side ofthe door I and the other to the same side of the door I. A padlock, I,secures the free ends of these sections of chain together. The chain M Mis so loose that force exerted by a jimmy or analogous implement toforce the door I open will be so far expended before it acts on thechain that the chain will not be broken. It is also long enough topermit the door to open sufliciently far to allow the short-circuitingdevice to operate and short-circuit the resistance-coil, so as to causean alarm at the oflice. It is not, however, long enough to admit aburglar past the door. The burglar endeavoring to effect an entranceinto the guarded building has still to sever the chain or break thepadlock. While he is engaged in efforts to do this the watchmen at theoifice will be afforded time to proceed toward the guarded building. llmay be frustrated in this =wa Preferably these chain-sections will compse swivels m m, so that they cannot be broken by twisting them.

The ends of the chain-sections MM may be united by the padlock when doorI is partially closed, and while the inmates of the guarded building areoutside the door. They can accomplish this by thrusting their handsbetween the door I and the door I, slipping the hasp of the padlockthrough the end links of the chain-sections, and then locking thepadlock. The door I may then be entirely closed and locked.

The keyH enables the inmates of the guarded building on returning to itto give a preconcerted signal, and thus indicate the diii'erence betweenthemselves'and a burglar to the watchmen at the office.

Obviously the improvement is applicableto articles other than doors.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The combination of an electric circuit extending between a guardedbuilding and an ofiice where watchmen are kept, a door or like articlein the guarded building, a lock, bolt, or analogous fastening for thedoor or like article, a circuit-closing device operating to fulfill itsfunction when the door or like article is opened partially, a chainpreventing the door or like article from being opened sulficiently wideto admit a burglar, but made of such length that the force by which thelock, bolt, or analogous fastening of the door or like article may bebroken will not act to break the chain, and of such length that it willpermit the door or like article to be opened wide enough for thecircuit-closing device to operate, substantially as specified.

2. The combination of an electric circuit extending between a guardedbuilding and an office where watchmen are kept, a door or like articlein the guarded building, a lock, bolt, or analogous fastening for thedoor or like ar-. ticle, a eircuit-closing device operating to fulfillits function when the door or like article is opened partially, a chaincomprising swivels and preventing the door or like article from beingopened sulllciently wide to admit a burglar, but made of such lengththat the force by which the lock, bolt, or analogous fastening of thedoor or like article may be broken will not act to break the chain, andof such length that it will permit the door or like article to be openedwide enough for the circuit-closing device to operate, substantially asspecified.

FRANK G. LYON.

Witnesses:

T. J. KEANE, WVILLIAM G. LIPsEY.

ayaburglary

